Method and apparatus for coordinating multi-user multi-access point transmissions

ABSTRACT

Aspects of the present disclosure generally relate to a wireless communication method in a wireless network comprising a plurality of access points (APs) sharing a communication channel, each AP is configured to manage stations of a basic service set (BSS), the method comprising at a coordinator AP: signaling to another AP, referred to as coordinated AP, that the coordinator AP has gained access to the communication channel; and sending to the coordinated AP a resource allocation allocating a chunk of the communication channel for stations managed by the coordinated AP.

CROSS REFERENCE TO RELATED APPLICATIONS

This application a continuation of U.S. patent application Ser. No.17/121,102, filed on Dec. 14, 2020, which claims the benefit under 35U.S.C. § 119(a)-(d) of United Kingdom Patent Application No. 1919090.9,filed on Dec. 20, 2019 and entitled “METHOD AND APPARATUS FORCOORDINATING MULTI-USER MULTI-ACCESS POINT TRANSMISSIONS” and PatentApplication No. 2000321.6, filed on Jan. 9, 2020 and entitled “METHODAND APPARATUS FOR COORDINATING MULTI-USER MULTI-ACCESS POINTTRANSMISSIONS”. The above-cited patent applications are incorporatedherein by reference in their entirety.

FIELD OF THE INVENTION

The invention relates to the technical field of wireless communicationnetworks, and more particularly methods and devices for coordinatingmultiple Access Points in Extremely High Throughput (EHT) systems.

BACKGROUND OF THE INVENTION

With the emergence of real-time applications such as online gaming,real-time video streaming, virtual reality, and remote-control drone androbots, new requirements and issues need to be taken into consideration,in particular in terms of latency and robustness. In this context, theIEEE 802.11 working group considered this problematic as a goal for thenext major 802.11 release (802.11be) and one of selected technologies isthe Multi-AP coordination strategy.

Multi-AP technology consists in enabling some degree of collaborationamong neighbouring EHT APs in order to have a more efficient utilizationof the limited time, frequency and spatial resources available. This isparticularly important when the neighbouring EHT APs operate over a sameselected channel. With such a technology, two neighbouring EHT APs mayshare resources in terms of frequency or time and, in this way, preventsinterferences. EHT APs that collaborate together to share resources arereferred to as coordinated APs. Moreover, the data transmissionestablished by coordinated APs is referred as Multi-AP transmission.

Typically, a Multi-AP coordination scheme is based on a coordinatedOFDMA scheme/sharing wherein coordinated EHT APs synchronise their datatransmissions, and use orthogonal time/frequency resources. The set ofthe collaborating EHT APs is referred to as Multi-AP group and a notionof coordinator/coordinated AP is introduced in order to operate aMulti-AP transmission. Basically, the coordinator AP is the EHT AP ofthe Multi-AP group that gains the medium access right for a given time(TXOP) on a given channel. The coordinator AP may then sharetime/frequency resources within the given time period betweencoordinated APs of the Multi-AP group. A coordinated AP schedules thendownlink (DL) and/or uplink (UL) transmissions for its associated non-APstations within the constraints of its allocated resources.

SUMMARY OF INVENTION

In such a context, the global objective of the invention is acommunication method for coordinating multiple Access Points.

An objective of embodiments of the invention is to specify acommunication method for initiating a multi-AP transmission by thecoordinator AP by advertising the EHT APs of the multi-AP group.

Another objective of embodiments of the invention is to specify a methodfor identifying which coordinated APs have the intention ofparticipating in the multi-AP transmission in order to compute anefficient coordinated APs resource allocation.

Yet another objective of embodiments of the invention is to specify amethod for retrieving the traffic needs of the coordinated APs whichhave the intention of participating in the multi-AP transmission inorder to compute a more efficient coordinated APs resource allocation.

The above objectives are addressed by one or more of the followingaspects of the present disclosure.

An aspect of the present disclosure provides a wireless communicationmethod in a wireless network comprising a plurality of access points(APs) sharing a communication channel, each AP is configured to managestations of a basic service set (BSS), the method comprising at acoordinator AP:

signaling to another AP, referred to as coordinated AP, that thecoordinator AP has gained access to the communication channel; and

sending to the coordinated AP a resource allocation allocating a chunkof the communication channel for stations managed by the coordinated AP,

wherein the resource allocation is determined based on resource needsprovided by the coordinated AP.

Another aspect of the present disclosure provides wireless communicationmethod in a wireless network comprising a plurality of access points(APs) sharing a communication channel, each AP is configured to managestations of a basic service set (BSS), the method comprising at acoordinator AP:

signaling to another AP, referred to as coordinated AP, that thecoordinator AP has gained access to the communication channel; and

sending to the coordinated AP a resource allocation allocating a chunkof the communication channel for stations managed by the coordinated AP,

wherein the resource allocation is determined by sharing the gainedcommunication channel between the plurality of APs without thecoordinated APs having provided their resource needs.

Yet a further aspect of the present disclosure provides a wirelesscommunication method in a wireless network comprising a plurality ofaccess points (APs) sharing a communication channel, each AP isconfigured to manage stations of a basic service set (BSS), the methodcomprising at a coordinator AP:

signaling to another AP, referred to as coordinated AP, that thecoordinator AP has gained access to the communication channel; and

sending to the coordinated AP a resource allocation allocating a chunkof the communication channel for stations managed by the coordinated AP,

wherein the signaling comprises a response type indication forindicating a response type expected from the coordinated AP.

Yet a further aspect of the present disclosure provides a wirelesscommunication method in a wireless network comprising a plurality ofaccess points (APs) sharing a communication channel, each AP isconfigured to manage stations of a basic service set (BSS), the methodcomprising at a coordinator AP that has gained access to thecommunication channel:

performing an intra-AP resource allocation by allocating a chunk of thecommunication channel for stations managed by the coordinator AP; and

sending to another AP, referred to as coordinated AP, a resourceallocation allocating, for stations managed by the coordinated AP, achunk from a remaining part of the communication channel not allocatedto stations managed by the coordinator AP.

Yet a further aspect of the present disclosure provides a wirelesscommunication method in a wireless network comprising a plurality ofaccess points (APs) sharing a communication channel, each AP isconfigured to manage stations of a basic service set (BSS), the methodcomprising at a coordinated AP:

receiving signaling that another AP, referred to as coordinator AP, hasgained access to the communication channel; and

providing, to the coordinator AP, resource needs of stations managed bythe coordinated AP.

Yet a further aspect of the invention relates to a non-transitorycomputer-readable medium storing a program which, when executed by amicroprocessor or computer system in a device, causes the device toperform any method as defined above.

At least parts of the methods according to the invention may be computerimplemented. Accordingly, the present invention may take the form of anentirely hardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects that may all generally bereferred to herein as a “circuit”, “module” or “system”. Furthermore,the present invention may take the form of a computer program productembodied in any tangible medium of expression having computer usableprogram code embodied in the medium.

Since the present invention can be implemented in software, the presentinvention can be embodied as computer readable code for provision to aprogrammable apparatus on any suitable carrier medium. A tangiblecarrier medium may comprise a storage medium such as a hard disk drive,a magnetic tape device or a solid-state memory device and the like. Atransient carrier medium may include a signal such as an electricalsignal, an electronic signal, an optical signal, an acoustic signal, amagnetic signal or an electromagnetic signal, e.g. a microwave or RFsignal.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the present invention will become apparent tothose skilled in the art upon examination of the drawings and detaileddescription. Embodiments of the invention will now be described, by wayof example only, and with reference to the following drawings:

FIG. 1 illustrates an example of a network environment in whichembodiments of the present disclosure may be implemented;

FIGS. 2 a, 2 b and 2 c illustrate examples of Time/Frequency resourcessharing schemes that can be envisaged in an enhanced multiple APcoordination system, in accordance with one or more example embodimentsof the present disclosure;

FIG. 3 illustrates a Multi-AP transmission which can be operated in anenhanced multiple AP coordination system, in accordance with one or moreexample embodiments of the present disclosure;

FIG. 4 illustrates the coordinated APs sharing initialization phase 400which can be operated in an enhanced multiple AP coordination system, inaccordance with one or more example embodiments of the presentdisclosure;

FIGS. 5 a and 5 b illustrate two frame formats relative to the frameCOORD_AP_SETUP_REQ based on a beacon frame, in accordance with one ormore example embodiments of the present disclosure;

FIG. 6 illustrates a frame format relative to the frameCOORD_AP_SETUP_REQ based on a non-HT DUP Trigger frame, in accordancewith one or more example embodiments of the present disclosure;

FIG. 7 illustrates a frame format relative to frame COORD_AP_SETUP_RESPincluding a coordinated APs Report, in accordance with one or moreexample embodiments of the present disclosure;

FIG. 8 illustrates a frame format relative to frame COORD_AP_SETUP_RESPincluding a coordinated APs Report based on a Frequency/Temporalresource request, in accordance with one or more example embodiments ofthe present disclosure;

FIG. 9 illustrates a frame format relative to frame COORD_AP_SETUP_RESPincluding a coordinated APs Report based on a Resource Unit allocationrequest, in accordance with one or more example embodiments of thepresent disclosure;

FIG. 10 illustrates the coordinated APs Resource Allocation phase whichcan be operated in an enhanced multiple AP coordination system, inaccordance with one or more example embodiments of the presentdisclosure;

FIG. 11 illustrates a frame format relative to frame COORD_AP_RES basedon a non-HT DUP Trigger frame, in accordance with one or more exampleembodiments of the present disclosure;

FIGS. 12 a and 12 b illustrate, using a flowchart, general stepsoperated by APs which can be operated in an enhanced multiple APcoordination system, in accordance with one or more example embodimentsof the present disclosure;

FIG. 13 illustrates the general steps performed by a coordinated AP at areception of COORD_AP_SETUP_REQ soliciting a response, in accordancewith one or more example embodiments of the present disclosure;

FIG. 14 illustrates the general steps performed by a coordinated AP forgenerating a coordinated AP report based on a Buffer Status Report, inaccordance with one or more example embodiments of the presentdisclosure;

FIG. 15 illustrates the general steps performed by a coordinated AP forgenerating a coordinated AP report based on an expected bandwidth andduration, in accordance with one or more example embodiments of thepresent disclosure;

FIG. 16 illustrates the general steps performed by a coordinated AP forgenerating a coordinated AP report based on the intra-AP resourceallocation, in accordance with one or more example embodiments of thepresent disclosure; and

FIG. 17 shows a schematic representation a communication device orstation according to embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates an example of a network environment in whichembodiments of the present disclosure may be implemented.

The illustrated network environment comprises an enhanced multiple EHTAP coordination system 100. The system contains three neighbouring APs110, 130 and 150 implementing the multi-AP technology. In the presentdisclosure, AP 110, AP 130 and AP 150 are also referred to,respectively, as AP1, AP2 and AP3.

Non-AP STAs are associated with the neighbouring APs 110, 130 and 150.In the illustrated example, non-AP STAs 115 and 118 are associated withAP 110, non-AP STA 135 is associated with AP 130 and non-AP STA 155 isassociated with AP 150.

The APs 110, 130 and 150 form a multi-AP group consisting in a set ofAPs having common features. In particular, they have the same ExtendedService Set (ESS) and are close enough to each other to communicate. TheAPs may operate over a same channel (corresponding to all or part of theoperational channel) and thus coordination is need to avoidinterference. A multi-AP group is either static or updated each time oneAP of the group gains access to the medium. It is assumed that each APof a multi-AP group knows at any time the composition (the list of APs)of the Multi-AP group. In other words, the APs are able to identify eachother.

It is assumed that AP 110 has gained access to the medium for a specificduration (COORD_TXOP) on specific operational channels (COORD_CHANNELS),and then has taken a role of coordinator for initiating a multi-APtransmission, i.e. AP 110 performs a time/frequency resources sharingwithin the duration COORD_TXOP and over the channels COORD_CHANNELSbetween the APs of the Multi-AP group. Other members of the Multi-APgroup (APs 130 and 150) are referred to as coordinated APs. For example,the duration COORD_TXOP is equal to 2 ms and the channels COORD_CHANNELScorrespond to an operational bandwidth of 80 MHz made of four 20 MHzchannels.

FIGS. 2 a, 2 b and 2 c illustrate examples of Time/Frequency resourcessharing schemes that can be envisaged in an enhanced multiple APcoordination system, in accordance with one or more example embodimentsof the present disclosure.

FIG. 2 a illustrates a coordinated OFDMA scheme/sharing 200. Thecoordinator AP shares frequency resource chunks over the channelsCOORD_CHANNELS with coordinated APs for the entire duration COORD_TXOP.Preferably, a frequency resource chunk is equal to 20 MHz so that an APmay reproduce legacy operations with its associated stations. In theillustrated example, coordinator AP1 (110) allocates for itselfresources corresponding to a frequency band 201 (referred to asAP1_COORD_CHANNELS) during a duration (referred to as AP1_COORD_TXOP)equal to COORD_TXOP. Coordinator AP1 (110) also allocates forcoordinated AP2 (130) resources corresponding to a frequency band 202(referred to as AP2_COORD_CHANNELS) during a duration (referred to asAP2_COORD_TXOP) equal to COORD_TXOP, and allocates for coordinated AP3(150) resources corresponding to a frequency band 203 (referred to asAP3_COORD_CHANNELS) during a duration (referred to as AP3_COORD_TXOP)equal to COORD_TXOP.

FIG. 2 b illustrates a coordinated TDMA scheme/sharing 230. Thecoordinator AP shares the entire frequency band (COORD_CHANNELS) intime. In the illustrated example, coordinator AP1 (110) allocates foritself resources corresponding to a frequency band AP1_COORD_CHANNELSequal to COORD_CHANNELS during a time period AP1_COORD_TXOP 231 (e.g. 1ms). Coordinator AP1 (110) also allocates for coordinated AP2 (130)resources corresponding to a frequency band AP2_COORD_CHANNELS equal toCOORD_CHANNELS during a time period AP2_COORD_TXOP 232 (e.g. 0.4 ms),and allocates for coordinated AP3 (150) resources corresponding to afrequency band AP3_COORD_CHANNELS equal to COORD_CHANNELS during a timeperiod AP3_COORD_TXOP 233 (e.g. 0.6 ms).

FIG. 2 c illustrates a coordinated OFDMA/TDMA scheme/sharing 260. In theillustrated example, coordinator AP1 (110) allocates for itselfresources corresponding to a frequency band AP1_COORD_CHANNELS equal toa portion (preferably multiple of 20 MHz) of COORD_CHANNELS during aduration AP1_COORD_TXOP equal to COORD_TXOP. Coordinator AP1 (110) alsoallocates for coordinated AP2 (130) resources corresponding to afrequency band AP2_COORD_CHANNELS equal to a portion (preferablymultiple of 20 MHz) of COORD_CHANNELS during a duration AP2_COORD_TXOP262 (e.g. 1 ms) and allocates for coordinated AP3 (150) resourcescorresponding to a frequency band AP3_COORD_CHANNELS equal to a portion(preferably multiple of 20 MHz) of COORD_CHANNELS during a durationAP3_COORD_TXOP 263 (e.g. 1 ms).

Note that a coordinator AP allocates time/frequency resources at APlevel. It means that the coordinator AP doesn't allocate Resource Units(RUs) directly for stations associated with the coordinated APs. Itremains the responsibility of the coordinated APs to allocate RUs fortheir associated STAs. In the following, resource allocation performedby the coordinator AP for sharing resources between APs is referred toas inter-AP resource allocation or coordinated AP (CAP) resourceallocation, and resource allocation performed by an AP for sharingresources with its associated stations is referred to as intra-APresource allocation. The inter-AP resource allocation may include for agiven AP one or more of the following parameters: allocatedchannels/subchannels, allocated duration, starting and ending times ofthe allocated duration.

FIG. 3 illustrates a Multi-AP transmission which can be operated in anenhanced multiple AP coordination system, in accordance with one or moreexample embodiments of the present disclosure.

Once gaining the medium by an AP (referred to as coordinator AP), amulti-AP transmission may be launched over the channel COORD_CHANNELSfor the duration COORD_TXOP 300.

The transmission is divided in 3 phases: a first phase 310 referred toas coordinated APs (CAP) sharing initialization phase, next a secondphase 320 referred to as CAP Resource Allocation sharing phase andfinally a third phase 330 referred to as CAP Data transmission phase.

Phase 310 corresponds to the sharing initialization phase and has twofunctions. During this phase, the coordinator AP indicates/signals tocoordinated APs that it gained the medium over the channelCOORD_CHANNELS for a duration COORD_TXOP and is ready to initiate amulti-AP transmission. Optionally, it may request a response from thecoordinated APs in order to know which coordinated APs intend toparticipate in the multi-AP transmission. Moreover, it may also requestthe resource needs of each coordinated AP which has the intention toparticipate. Phase 310 is described in more details according to oneimplementation with reference to FIG. 4 .

Phase 320 corresponds to the CAP Resource Allocation sharing phase.During this phase, the coordinator AP transmits for each coordinated APthe CAP resource Allocation corresponding for example to the allocatedsubchannels (preferably multiple of 20 MHz), allocated TXOP duration andTransmission start time. In other words, each coordinated APi receivesthe following parameters: APi_COORD_CHANNELS, APi_COORD_TXOP andAPi_COORD_START. Phase 320 is described in more details according to oneimplementation with reference to FIG. 10 .

Phase 330 corresponds to the CAP Data transmission phase. During thisphase, according to the received CAP resource Allocation, each APi(coordinator AP and each coordinated AP) transmits data on itsrespective allocated subchannels APi_COORD_CHANNELS for the allocatedTXOP duration APi_COORD_TXOP at the transmission start timeAPi_COORD_START. In other words, the coordinated AP computes itsIntra-AP Resource Allocation in order to schedule the DL and ULtransmissions to its associated non-AP stations under the constraints ofthe CAP (inter-AP) resource Allocation.

According to an embodiment of the invention, phase 310 is omitted. Insuch a case, the coordinator AP computes the coordinated APs resourceAllocation by considering all APs of the multi-AP group, i.e. not onlyfrom the APs which have the intention to participate in the multi-APtransmission. For instance, the coordinator AP may first allocate toitself resources according to its resource needs and then allocateuniformly the rest of available resources between all the coordinatedAPs of the multi-AP group. Advantageously, as no messages are exchangedduring the initialization phase, bandwidth is saved and processing timeis reduced for the coordinator APs. On the other hand, omitting phase310 may result into a sub-optimal resource allocation, e.g. in casewhere resources are allocated for an AP that may not have the intentionto participate in the multi-AP transmission.

FIG. 4 illustrates the coordinated APs sharing initialization phase 400which can be operated in an enhanced multiple AP coordination system, inaccordance with one or more example embodiments of the presentdisclosure.

First, the coordinator AP indicates/signals to coordinated APs that itgained the medium over the channel COORD_CHANNELS for a durationCOORD_TXOP and is ready to initiate a multi-AP transmission. It isperformed by the sending of a frame 410 referred to asCOORD_AP_SETUP_REQ.

Frame COORD_AP_SETUP_REQ is basically a non-high throughput (non-HT)duplicate (DUP) frame meaning that its transmission is duplicated overtwo or more 20 MHz channels which allows a station in a non-HT basicservice set (BSS) on any one of the 20 MHz channels to receive thetransmission.

According to an embodiment of the invention, the frameCOORD_AP_SETUP_REQ 410 is a beacon or probe response frame with adedicated subfield indicating that it is sent by an AP coordinator. Aframe format according to one implementation is described with referenceto FIG. 5 a or 5 b.

According to another embodiment of the invention, the frameCOORD_AP_SETUP_REQ 410 is a non-HT DUP Trigger frame with a dedicatedsubfield indicating that it is a frame sent by an AP coordinator forinitiating a multi-AP transmission. A frame format according to oneimplementation is described with reference to FIG. 6 .

According to some embodiments of the invention, dedicated frames 420 and421 referred to as COORD_AP_SETUP_RESP frames need to be sent by the APsof the Multi-AP group which have the intention to participate to theMulti-AP transmission. Those APs are here considered coordinated APs. Inthe present disclosure, three response procedures are described:

-   -   For the first one, the coordinator AP1 110 doesn't expect a        response (COORD_AP_SETUP_RESP frame) from any APs of the        Multi-AP group. In such a case, no frame COORD_AP_SETUP_RESP is        sent by any Coordinated AP.    -   For the second one, the coordinator AP1 110 requests APs of the        multi-AP group which have the intention to participate to the        Multi-AP transmission to send a response. In such a case, a        frame COORD_AP_SETUP_RESP 420 is sent by AP2 130 to AP1 110 and        a frame COORD_AP_SETUP_RESP 421 is sent by AP3 150 to AP1 110.    -   For the third one, the coordinator AP1 110 requests explicitly a        report about the resource needs (referred to as coordinated AP        Report, or CAP Report) from the coordinated APs of the Multi-AP        group which have the intention to participate to the Multi-AP        transmission. In such a case, a frame COORD_AP_SETUP_RESP 420 is        sent by AP2 130 including its CAP Report to AP1 110 and a frame        COORD_AP_SETUP_RESP 421 is sent by AP3 150 including its CAP        Report to AP1 110.

According to embodiments of the invention, three implementations of thecoordinated APs Reports are described with reference to FIGS. 7, 8 and 9. More precisely, FIG. 7 illustrates a frame format relative to frameCOORD_AP_SETUP_RESP including a coordinated APs Report based on a BufferStatus report. FIG. 8 illustrates a frame format relative to frameCOORD_AP_SETUP_RESP including a coordinated APs Report based on aFrequency/Temporal resource request. And FIG. 9 illustrates a frameformat relative to frame COORD_AP_SETUP_RESP including a coordinated APsReport based on a RU allocation request.

FIGS. 5 a and 5 b illustrate two frame formats relative to the frameCOORD_AP_SETUP_REQ based on a beacon frame, in accordance with one ormore example embodiments of the present disclosure. The two frameformats can be used in combination.

According to an embodiment of the invention, a new information element500 relative to Multi-AP, referred to as Multi-AP element, is defined.The Multi-AP element may be set optional in a beacon frame, such as theframe COORD_AP_SETUP_REQ previously described.

According to a first embodiment, illustrated by FIG. 5 a , the Multi-APelement 500 contains three subfields: An Element ID subfield 510, acoordinator AP ID subfield 511 and a Response Type subfield 512.

The Element ID subfield 510 identifies the element as a Multi-APelement. It may take a value in the range 245-254, so far reserved in802.11. For the purpose of illustration, the value 246 is chosen in theembodiments of the invention.

The coordinator AP ID subfield 511 corresponds to an identifier of thecoordinator AP. Preferably, it is equal to the BSSID of the coordinatorAP.

The Response type subfield 512 indicates the response type expected bythe coordinator AP from APs of the multi-AP group. Three response typesmay be defined as illustrated by the tab 520.

A first response type indicates that the coordinator AP doesn't expect aresponse (COORD_AP_SETUP_RESP frame) from any AP of the Multi-AP group.For the purpose of illustration, the encoding value is 0.

A second response type indicates that the coordinator AP requests theAPs of the multi-AP group which have the intention to participate to theMulti-AP transmission to send a response. Each response is contained ina dedicated COORD_AP_SETUP_RESP frame. For the purpose of illustration,the encoding value is 1.

A third response type indicates that the coordinator AP requestsexplicitly a CAP Report (corresponding to the resource needs) of APs ofthe Multi-AP group which have the intention to participate to theMulti-AP transmission. Each CAP Report is contained in a dedicatedCOORD_AP_SETUP_RESP frame. For the purpose of illustration, the encodingvalue is 2.

According to a second embodiment (in combination or alternate to thefirst embodiment), illustrated by FIG. 5 b , the Multi-AP element 500contains 2 subfields: An Element ID subfield 510 and a Start Multi-APTransmission subfield 513. The Start Multi-AP Transmission subfield 513corresponds to a Boolean set by an AP for indicating that it becomes acoordinator AP, for example when set to 1. By default, its value is 0.

FIG. 6 illustrates a frame format relative to the frameCOORD_AP_SETUP_REQ based on a non-HT DUP Trigger frame, in accordancewith one or more example embodiments of the present disclosure.

A trigger frame contains several fields and in particular it includes asingle Common Info field and a plurality of User Info fields.

The single Common Info field contains in particular a 4-bit Trigger Typesubfield (the first 4 bits in the Common Info field). The Trigger Typesubfield identifies the Trigger frame variant and several Trigger Typesubfield values have been defined in the 802.11ax standard. In theversion D6.0 of the standard, values between 8 and 15 are reserved andmay be used for defining new trigger frame variant.

For the present disclosure, new trigger frame variants are definedcorresponding each one to a specific frame COORD_AP_SETUP_REQ. In otherwords, a frame COORD_AP_SETUP_REQ 600 is a trigger frame identified by anew trigger frame variant defined within the Trigger Type subfield 650of the Common Info field 620.

A first new trigger frame variant is defined corresponding to a frameCOORD_AP_SETUP_REQ requesting no response from any APs of the Multi-APgroup. For the purpose of illustration, the Trigger Type subfield valuefor such a frame COORD_AP_SETUP_REQ is 8.

A second new trigger frame variant is defined corresponding to a frameCOORD_AP_SETUP_REQ requesting explicitly a response of presence for theAPs of the Multi-AP group which have the intention to participate to theMulti-AP transmission. Each response is contained in a dedicated frameCOORD_AP_SETUP_RESP. For the purpose of illustration, the Trigger Typesubfield value for such a frame COORD_AP_SETUP_REQ is 9.

A third new trigger frame variant is defined corresponding to a frameCOORD_AP_SETUP_REQ requesting explicitly a coordinated APs Report(corresponding to the resource needs) of APs of the Multi-AP group whichhave the intention to participate to the Multi-AP transmission. Eachcoordinated APs Report is contained in a dedicated frameCOORD_AP_SETUP_RESP. For the purpose of illustration, the Trigger Typesubfield value for such a frame COORD_AP_SETUP_REQ is 10.

According to several embodiments of the invention, all configurationsare possible in the specifications of the new trigger frames. Indeed,only one trigger frame variant may be used amongst the three, or two ofthem, or the three ones.

For the second and third frame variant, the plurality of User Infofields 630 may be used in order to allocate resources for the responseof the coordinated APs. More precisely, a User Info field 640 includesinformation corresponding to attributes of data that the respectivestations need to follow for participating in the MU UL PPDUtransmission. In particular, it contains an AID12 subfield 641 whichcarries the 12 LSBs of the Association Identifier (AID) of the stationfor which the user info filed is intended. In such a case, theconsidered RU is considered as scheduled RU. On the other hand, an AID12subfield 641 equal to 0 indicates a random RU.

In the context of the invention, according to a first embodiment, thetrigger frame 600 includes a plurality of User Info fields 630 for whichthe AID12 subfield 641 is set to 0 for each one. According to a secondembodiment, the trigger frame 600 contains a list of N User Info fields630, N being the number of AP included in the multi-AP group less one(corresponding to the coordinator AP). Each User Info fields 640 isdedicated to an AP included in the multi-AP group and is identified bythe AID12 subfield 641, set to a value corresponding to a specific AIDgiven to the AP of the multi-AP group. Moreover, for each User Infofields, the RU Allocation subfield 642 contains the RU allocated to theassociated AP for which this one must send its response.

Note that the AID of a station is a value assigned by an Access Point toa non-AP station during the association procedure that represents the16-bit ID of a STA. The MU UL access scheme uses the 12 LSBs of the AIDof the STA (referred to as AID12) of the station in order to indicatethe UL RU assignments in the trigger frame. Values between 2008 and 4095are authorized and more specially the value between 2008 and 2044 arereserved. Consequently, according to embodiments of the invention, aspecific AID may be assigned for each APs of the multi-AP group.

For the second frame variant, according to another embodiment, thecoordinated APs may also use a NDP (Null Data Packet) feedback reportprocedure for indicating their intention to participate in the multi-APtransmission. In such case, the format of the User Info field of thetrigger frame 650 is different and corresponds to 660. In particular,the User Info field contains a Starting AID subfield 661 and a FeedbackType subfield 662. The Starting AID subfield 661 defines the first AIDof the range of AIDs that are scheduled to respond to the NFRP Triggerframe and in the context of the present disclosure corresponds to thefirst specific AID assigned to the coordinated AP of the range ofspecific AIDs that are scheduled. The Feedback Type subfield 650specifies the type of the feedback. Only the value 0 is alreadyspecified and corresponds to a response of a resource request. Accordingto an embodiment of the invention, a new value is defined (forillustrative purpose set to 1) and corresponds to a response of a frameCOORD_AP_SETUP_REQ.

FIG. 7 illustrates a frame format relative to frame COORD_AP_SETUP_RESPincluding a coordinated APs Report, in accordance with one or moreexample embodiments of the present disclosure.

Frame COORD_AP_SETUP_RESP corresponds to a 802.11 frame sent by a APincluding a HE variant HT Control field 710. The HE variant HT Controlfield contains a list of Control subfields. Each control subfieldcontains a Control ID subfield and a Control Information subfield. Moreprecisely, the Control ID subfield indicates the type of informationcarried in the Control Information subfield. The values of the ControlID subfield and the associated length of the Control Informationsubfield may be conventional.

A control subfield is dedicated to the Buffer Status Reports (BSR) inorder to deliver buffer status information typically used for UL MUoperation. It is referred to as BSR Control subfield. In particular, itis identified by a Control ID subfield set to 3.

According to an embodiment of the invention, a frame COORD_AP_SETUP_RESPcorresponds to an 802.11 frame 700 including a HE variant HT Controlsubfield 710 which contains a BSR Control subfield 720 including aControl ID subfield 730 set to 3 and a Control Information subfield 740.In particular, it contains an ACI Bitmap subfield 741, a Delta TIDsubfield 742, an ACI high subfield 743, a Scaling Factor subfield 744, aQueue Size High subfield 745 and a Queue Size All subfield 746.

The ACI Bitmap subfield 741 indicates the access categories for whichthe buffer status is reported. Each bit of the ACI Bitmap subfield isset to 1 to indicate the buffer status of the corresponding AC, and setto 0 otherwise. If the ACI Bitmap subfield is 0 and the Delta TIDsubfield is 3 it indicates that there is buffered traffic for all 8TIDs.

The Delta TID subfield 742, together with the values of the ACI Bitmapsubfield, indicate the number of TIDs for which the AP is reporting thebuffer status.

The ACI High subfield 743 indicates the ACI of the AC for which the BSRis indicated in the Queue Size High subfield.

The Scaling Factor subfield 744 indicates the unit SF, in octets, of theQueue Size High and Queue Size All subfields.

The Queue Size High subfield 745 indicates the amount of bufferedtraffic, in units of SF octets, for the AC identified by the ACI Highsubfield that is intended for the AP identified by the receiver addressof the frame containing the BSR Control subfield.

The Queue Size All subfield 746 indicates the amount of bufferedtraffic, in units of SF octets, for all the ACs identified by the ACIBitmap subfield that is intended for the AP identified by the receiveraddress of the frame containing the BSR Control subfield.

FIG. 8 illustrates a frame format relative to frame COORD_AP_SETUP_RESPincluding a coordinated APs Report based on a Frequency/Temporalresource request, in accordance with one or more example embodiments ofthe present disclosure.

Frame COORD_AP_SETUP_RESP corresponds to an 802.11 frame including a HEvariant HT Control subfield. The HE variant HT Control subfield containsa list of Control subfields. Each Control subfield contains a Control IDsubfield and a Control Information subfield. More precisely, the ControlID subfield indicates the type of information carried in the ControlInformation subfield. The values of the Control ID subfield and theassociated length of the Control Information subfield may be the same asthose defined in 802.11ax standard, D6.0.

According to an embodiment of the invention, a new value is added forspecifying a control subfield specific to AP Traffic Needs, referred toas AP Traffic Needs Control subfield 820. For the purpose ofillustration, the value 7 has been selected for identifying the APTraffic Needs Control subfield 820 (tab 837, line 835).

Moreover, the AP Traffic Needs Control subfield 820 contains a specificControl Information subfield 840. The Control Information subfield 840contains two subfields, an Expected BW subfield 850 and an ExpectedDuration subfield 851. The Expected BW subfield 850 is coded on 2 bits.A value of 0 indicates a value of bandwidth equal to 20 MHz, a value of1 indicates a value of bandwidth equal to 40 Mhz, a value of 2 indicatesa value of bandwidth equal to 80 Mhz and a value of 3 indicates a valueof bandwidth equal to 80+80 Mhz or 160 Mhz. The Expected Durationsubfield 851 is coded on 16 bits.

Finally, a Frame COORD_AP_SETUP_RESP corresponds to an 802.11 frame 800including a HE variant HT Control subfield 810 which contains an APTraffic Needs Control subfield 820.

FIG. 9 illustrates a frame format relative to frame COORD_AP_SETUP_RESPincluding a coordinated APs Report based on a Resource Unit allocationrequest, in accordance with one or more example embodiments of thepresent disclosure.

Frame COORD_AP_SETUP_RESP corresponds to an 802.11 frame sent by an APincluding a HE variant HT Control subfield. The HE variant HT Controlfield contains a list of Control subfields. Each control subfieldcontains a Control ID subfield and a Control Information subfield. Moreprecisely, the Control ID subfield indicates the type of informationcarried in the Control Information subfield. The values of the ControlID subfield and the associated length of the Control Informationsubfield may be the same as those defined in 802.11ax standard, D6.0.

According to an embodiment of the invention, a new value is added forspecifying a control subfield specific to AP Traffic Needs, referred toas AP Traffic Needs Control subfield 820. For the purpose ofillustration, the value 7 has been selected for identifying the APTraffic Needs Control subfield 920.

Moreover, the AP Traffic Needs Control subfield 920 contains a specificControl Information subfield 940. The Control Information subfield 940contains a list of User Info Field 950. Among the list of User InfoField 950, a dedicated one is specific to the AP (960) and the othersrelative to the associated non-AP STAs associated to the AP (970).

The format of the User Info Field 960 corresponds also to the User Infofields format for a trigger frame excepted to AID12 subfield which isomitted. Moreover, it is placed in first position in the list of UserInfo Field 950.

The format of the User Info Field 970 relative to the associated non-APSTAs corresponds to the User Info fields format for a trigger frame. Inparticular, it contains an AID12 subfield 971 and a RU Allocationsubfield 972.

Finally, a Frame COORD_AP_SETUP_RESP corresponds to an 802.11 frame 900including a HE variant HT Control subfield 910 which contains an APTraffic Needs Control subfield 920.

FIG. 10 illustrates the coordinated APs Resource Allocation phase 1000which can be operated in an enhanced multiple AP coordination system, inaccordance with one or more example embodiments of the presentdisclosure.

The coordinator AP transmits for each coordinated APs the coordinatedAPs resource Allocation corresponding to the allocated channels(multiple of 20 MHz), allocated TXOP duration, and Transmission starttime. In other words, each coordinated APi receives the followingparameters: APi_COORD_CHANNELS, APi_COORD_TXOP and APi_COORD_START.

According to a first embodiment of the invention, the coordinated APsresource Allocation is computed without feedback of the coordinated APsin terms of intention to participate to the Multi-AP transmission (andoptionally their traffic needs). According to another embodiment of theinvention, the coordinated APs resource Allocation is computed byconsidering feedbacks of the APs which have intention to participate tothe Multi-AP transmission and optionally their Traffic needs. Thesefeedbacks have been extracted from the frames COORD_AP_SETUP_RESP420/421 sent by coordinated APs.

The coordinated APs resource Allocation is sent through a frameCOORD_AP_RES 1010 intended to coordinated APs. At the current stage, noframe format is proposed by the prior-art. A frame format is describedfor frame COORD_AP_RES with reference to FIG. 11 .

FIG. 11 illustrates a frame format relative to frame COORD_AP_RES basedon a non-HT DUP Trigger frame, in accordance with one or more exampleembodiments of the present disclosure.

A trigger frame 600 contains several fields and in particular itincludes a single “Common Info” field 620 and a plurality of “User Info”fields 630.

The single Common Info field contains in particular a 4-bit Trigger Typesubfield (the first 4 bits in the “Common Info” field). The Trigger Typesubfield identifies the Trigger frame variant and several Trigger Typesubfield values are envisaged. In version D6.0 of 802.11ax standard,values between 8 and 15 are reserved and may be used for defining newtrigger frame variant.

For the present disclosure, a new trigger frame variant is definedcorresponding to a specific frame COORD_AP_RES. For the purpose ofillustration, the Trigger Type subfield (1150) value for such a frameCOORD_AP_RES is 11 (1160).

Frame COORD_AP_RES 1100 is consequently a trigger frame 1100 whichcontains a Common Info field 1120 for which the trigger type subfield1150 is set to value 11. The other subfields of the Frame COORD_AP_RES1100 are similar to the subfields of TF 600 excepted to the list of UserInfo field 1130. Indeed, a specific User Info field 1140 is specifiedfor a frame COORD_AP_RES.

According to an embodiment of the invention, it contains an AP IDsubfield 1141, a coordinated AP Channels subfield 1142, a coordinated APTXOP subfield 1143 and an AP coordinated AP TX Start 1144. According toanother embodiment of the invention, it contains only an AP ID subfield1141 and a coordinated AP Channels subfield 1142. According to anotherembodiment of the invention, it contains only a coordinated AP TXOPsubfield 1143 and a coordinated AP TX Start subfield 1144.

FIGS. 12 a and 12 b illustrate, using a flowchart, general stepsoperated by APs which can be operated in an enhanced multiple APcoordination system, in accordance with one or more example embodimentsof the present disclosure.

FIG. 12 a illustrates the general steps performed by a coordinator APfor operating a Multi-AP Transmission.

At Step 1200, an AP of a multi-AP group gained the medium over thechannel COORD_CHANNELS for a duration COORD_TXOP and is ready toinitiate a multi-AP transmission. As such, it becomes during thisduration the coordinator AP of the AP multi-group.

At step 1205, the coordinator AP sends a frame COORD_AP_SETUP_REQ toinitiate the Multi-AP transmission.

According to an embodiment of the invention, the format of the frameCOORD_AP_SETUP_REQ is based on a beacon frame as described withreference to FIG. 5 a . It contains a Multi-AP Element 500 identified byan Element ID field set to 246. The coordinator AP ID subfield 511 isthe identifier of the coordinator AP. According to an embodiment of theinvention, it corresponds to the BSSID of the coordinator AP. Accordingto another embodiment of the invention, it corresponds to a specificAID. The AID assignment for an AP procedure is out the scope of theinvention. The Response type subfield 512 indicates the response typeexpected by the coordinator AP by APs of the multi-AP group. Its valueis either 0, 1 and 2. The selection of this value is either fixed ordynamic. At the stage, it is out of scope of the invention.

According to another embodiment of the invention, the format of theframe COORD_AP_SETUP_REQ is based on a beacon frame as described withreference to FIG. 5 b . It contains a Multi-AP Element 500 identified byan Element ID 510 subfield set to 246. It also contains a Start Multi-APTransmission subfield 513 set to 1.

According to an embodiment of the invention, the format of the frameCOORD_AP_SETUP_REQ is based on a non-HT DUP Trigger frame 600 asdescribed with reference to FIG. 6 . The selection of the trigger framevariant relative to multi-AP operation and corresponding to the responsetype expected by the coordinator AP is out of scope of the invention.According to the selected trigger frame variant, the Trigger Typesubfield 650 of the Common Info field 620 is set to 8, 9 or 10.Moreover, the list of User Info fields 630 is updated. According to afirst embodiment, the trigger frame 600 includes a plurality of UserInfo fields 630 for which the AID12 subfield 641 is set to 0 for eachone. According to a second embodiment, the trigger frame 600 contains alist of N User Info fields 630, N being the number of AP included in themulti-AP group less one (corresponding to the coordinator AP). Each UserInfo fields 640 is dedicated to an AP included in the multi-AP group andis identified by the AID12 subfield 641, set to a value corresponding toa specific AID given to the AP of the multi-AP group. Moreover, for eachUser Info field, the RU Allocation subfield 642 is updated indicatingthe RU allocated to the associated AP that it must transmit its response(COORD_AP_RESP).

According to another embodiment the format of the frameCOORD_AP_SETUP_REQ is based on a non-HT DUP Trigger frame correspondingto a NDP feedback report procedure. In such a case, the Trigger Typesubfield 650 of the Common Info field 620 is set to value 7. Asdescribed in FIG. 6 , the format of the User Info field of the frameCOORD_AP_SETUP_REQ is specific. A User Info Field 660 contains inparticular a Starting AID field 661 and a Feedback Type field 662. TheStarting AID field 661 is set to the first AID of the range of specificAIDs given to the AP of the multi-AP group. The Feedback Type subfield662 is set to 1.

Next, according to the response type expected by the coordinator AP, atstep 1210 (optional), the coordinator AP may receive a set of framesCOORD_AP_SETUP_RESP indicating the APs of the multi-AP group which havethe intention to participate to the Multi-AP transmission and accordingto an embodiment of the invention containing in addition coordinated APsReport (corresponding to the resource needs).

Next, at step 1215, with or without feedbacks of the APs in terms ofintention to participate to the Multi-AP transmission and optionallytheir Traffic needs, the coordinator AP computes a coordinated APsresource Allocation corresponding to the allocated channels (multiple of20 MHz) and/or allocated TXOP duration and/or Transmission start timefor each coordinated AP. Each coordinated APi receives the followingparameters: APi_COORD_CHANNELS, APi_COORD_TXOP and APi_COORD_START.

According to several embodiments of the invention, the coordinated APsresource Allocation may rely on several Time/Frequency resourcesscheme/sharing as described in FIG. 2 . According to an embodiment, thecoordinated APs Resource Allocation is based on a coordinated OFDMAscheme/sharing as described in FIG. 2 a . According to anotherembodiment, the coordinated APs Resource Allocation is based on acoordinated TDMA scheme/sharing as described in FIG. 2 b . According toanother embodiment, the coordinated APs resource Allocation is based ona coordinated OFDMA/TDMA scheme/sharing as described in FIG. 2 c .According to another embodiment, the coordinated APs resource Allocationmay be dynamic and may alternate between OFDMA, TDMA and OFDMA/TDMAscheme/sharing.

Next, at step 1220, coordinator AP sends a frame COORD_AP_RES to allcoordinated APs of the Multi-AP group including the computed coordinatedAPs resource allocation. The format of the frame COORD_AP_RES 1100 isdescribed with reference to FIG. 11 . In particular the list of UserInfo field 1130 is constructed at step 1220. For each coordinated APi,the subfields of its corresponding user Info Field are set as following:the AP ID subfield 1141 is set to the specific AID of the coordinatedAPi, the coordinated AP Channels subfield 1141 is set toAPi_COORD_CHANNELS, the coordinated AP TXOP subfield 1142 is set toAPi_COORD_TXOP and the AP coordinated AP TX Start 1143 is set toAPi_COORD_START. According to embodiment of the invention, it is notnecessary to fulfil all subfields 1142,1143 or 1144. For instance, for acoordinated APs resource Allocation based on a coordinated OFDMA, thecoordinated AP TXOP subfield 1143 and coordinated AP TX Start subfield1144 may be omitted. Similarly, for a coordinated APs resourceAllocation based on a coordinated TDMA, the coordinated AP Channelssubfield 1142 may be omitted.

FIG. 12 b illustrates the general steps performed by a coordinated AP ata reception of a frame COORD_AP_RES.

At a reception of a frame COORD_AP_RES (stet 1270), the coordinated APextracts (1275) from coordinated APs resource allocation included in theframe its respective allocated resources. More precisely, it extractsthe User Info field 1130 for which the AP ID subfield 1141 correspondsto its specific AID and retrieves the available subfields,APi_COORD_CHANNELS and/or to APi_COORD_TXOP and/or APi_COORD_START.

Next, at step 1280 coordinated AP computes or updates its Intra-APResource Allocation according to (constrained by) the resourcesallocated by the coordinator AP given by the parametersAPi_COORD_CHANNELS and/or to APi_COORD_TXOP and/or APi_COORD_START.

Next, at step 1285 starts its data transmission according to itscomputed intra-AP resource allocation.

FIG. 13 illustrates the general steps performed by a coordinated AP at areception of COORD_AP_SETUP_REQ soliciting a response, in accordancewith one or more example embodiments of the present disclosure.

At the reception of a COORD_AP_SETUP_REQ soliciting a response (step1300), an EHT decides or not whether it has the intention to participateor not.

First, at step 1310, the coordinated AP computes its traffic needs. Itscomputation is out of the scope of the invention but typically, it isbased on the buffer status reports (BSRs) delivered by the non-AP STAsassociated with the coordinated AP.

Next, at step 1320, from the computed traffic needs at step 1310, thecoordinated AP decides or not whether it has the intention toparticipate in the multi-AP transmission operated by the coordinator AP.If yes, next step is 1360. If not, next step is 1340 corresponding tothe end of the algorithm. The choice of intending or not according tothe traffic needs is out of the scope of the invention but typically itdepends on the traffic needs computed at step 1310.

Next, step 1360 checks whether a coordinated AP report needs to begenerated or not. If yes, next step is 1380. If not, next step is 1370.The check is directly derived of the type of the frameCOORD_AP_SETUP_REQ. According to an embodiment of the invention forwhich the frame COORD_AP_SETUP_REQ is based on a non-HT DUP Triggerframe as described with reference to FIG. 6 , this step consists inreading the Trigger Type subfield value 650 of the Common Info field andif it is set to 9, the coordinated AP doesn't need to generate acoordinated AP report. But if it is set to 10, the coordinated AP needsto generate a coordinated AP report. According to another embodiment ofthe invention for which the frame COORD_AP_SETUP_REQ is based on abeacon frame as described with reference to FIG. 5 , this step consistsin reading the “Response type” value 512 of the Multi-AP Element 500. Ifit is set to 1, the coordinated AP doesn't need to generate acoordinated AP report. But if it is set to 2, the coordinated AP needsto generate a coordinated AP report.

At step 1370 a COORD_AP_RESP frame is sent intended to the coordinatorAP indicating that it has the intention to participate to the Multi-APtransmission. For instance, a COORD_AP_RESP corresponds to an HE TBfeedback NDP as specified IEEE 802.11ax, version D6.0.

At step 1380 a frame COORD_AP_RESP is generated including a coordinatedAP report. Several methods are proposed in the present disclosure.According to a first method, the coordinated AP report corresponds to aBuffer Status Report. It is described with reference to FIG. 14 and itis sent within a frame COORD_AP_RESP described with reference to FIG. 7. According to a second one, the coordinated AP report corresponds to abandwidth and duration expected values. It is described with referenceto FIG. 15 and it is sent within a frame COORD_AP_RESP described withreference to FIG. 8 . According to a third one, the coordinated APreport corresponds to the Intra-AP Resource Allocation of thecoordinated AP. It is described with reference to FIG. 16 and it is sentwithin a frame COORD_AP_RESP described with reference to FIG. 9 .

At step 1390, the frame COORD_AP_RESP is sent to coordinator AP.

FIG. 14 illustrates the general steps performed by a coordinated AP forgenerating a coordinated AP report based on a Buffer Status Report, inaccordance with one or more example embodiments of the presentdisclosure.

A non-AP STA delivers buffer status reports (BSRs), in particular toassist its AP in computing its Intra-AP Resource Allocation. The non-APSTA can either implicitly deliver BSRs in the QoS Control subfield orBSR Control subfield of any frame transmitted to the AP (unsolicitedBSR) or explicitly deliver BSRs in any frame sent to the AP in responseto a BSRP Trigger frame (solicited BSR). The buffer status reported inthe QoS Control subfield consists of a queue size value for a given TID(see 9.2.4.5.6 (Queue Size subfield)). The buffer status reported in theBSR Control subfield, referred to as buffer status information, consistsof an ACI bitmap, delta TID, a high priority AC, and two queue sizes.

Consequently, at each reception of a BSR i of an associated STA i, an APstores the buffer status information BSI(STAi) contained in the receivedBSR of the STAi.

When a coordinated AP needs to generate a coordinated AP report (step1380), according to an embodiment of the invention, it performs thesteps 1410 and 1420.

At step 1410, the coordinated AP report retrieves its own buffer statusinformation BSI(AP) similarly as it's done with its associated STA.

Next step 1420, the coordinator AP generates the coordinated AP reportfrom its BSI(AP=STA0) and the buffer status information BSI(STAi) of allits associated non-AP STAs. More precisely, a global buffer statusinformation is computed from its BSI(AP=STA0) and the buffer statusinformation BSI(STAi) of all its associated non-AP STAs. Its computationis the following:

A buffer status information BSI(STAi) of an associated STA i isrepresented by the following parameters: ACI bitmap(STAi), delta TID(STAi), ACI High (STAi), Queue Size High(STAi) and Queue Size All(STAi). The value of I equal to 0 corresponding to the buffer statusinformation of the coordinated AP.

The global buffer status information is represented by the followingparameters: ACI bitmap(G), delta TID (G), ACI High (G), Scaling Factor(G), Queue Size High(G) and Queue Size All (G).

The ACI Bitmap subfield indicates the access categories for which thebuffer status is reported. More precisely,

Each bit j of the ACI Bitmap is dedicated to an access category. The jthbit of ACI bitmap(G) is set to 1 if the jth bit of at least one ACIbitmap(STAi) is set to 1.

The Delta TID subfield, together with the values of the ACI Bitmapsubfield, indicate the number of TIDs for which a STA is reporting thebuffer status. delta TID (G) is equal to the number of different TIDbetween all the STAi. It is directly computed from ACI bitmap(STAi) andDelta TID (STAi)

The ACI High subfield indicates the ACI of the AC for which the BSR isindicated in the Queue Size High subfield. ACI High (G) corresponds tothe maximum occurrence between the set of the ACI High (STAi).

The Queue Size High subfield indicates the amount of buffered traffic,in units of SF octets, for the AC identified by the ACI High subfieldthat is intended for a STA identified by the receiver address of theframe containing the BSR Control subfield. Queue Size High (G)corresponds to the sum of all Queue Size High (STAi).

The Queue Size All subfield indicates the amount of buffered traffic, inunits of SF octets, for all the ACs identified by the ACI Bitmapsubfield that is intended for the STA identified by the receiver addressof the frame containing the BSR Control subfield. Queue Size All (G)corresponds to the sum of all Queue Size All (STAi).

According to the value of Queue Size All (G), the Scaling Factor (G) isselected.

Finally, the coordinated AP report is included within a frameCOORD_AP_RESP 700 as described with reference to FIG. 7 . Moreprecisely, ACI bitmap(G) is included in the subfield 741, delta TID (G)is included in the subfield 742, ACI High (G) is included in thesubfield 743, Scaling Factor (G) is included in the subfield 744, QueueSize High(G) is included in the subfield 745 and Queue Size All (G) isincluded in the subfield 746.

FIG. 15 illustrates the general steps performed by a coordinated AP forgenerating a coordinated AP report based on an expected bandwidth andduration, in accordance with one or more example embodiments of thepresent disclosure.

Preferably, an AP computes an Intra-AP Resource Allocation in order toschedule Its DL and UL transmissions with its associated STAs. ItsIntra-AP Resource Allocation is allocated over given operating channelsof the AP corresponding to a given bandwidth, referred to as “expectedBW” and a given period of time, referred to as “expected Duration”.

When a coordinated AP needs to generate a coordinated AP report (step1380), according to an embodiment of the invention, at step 1510, itretrieves the bandwidth “Expected Bandwidth” and the duration “ExpectedDuration”, which corresponds to the coordinated AP Report. Typically, atthis instant, the coordinated AP has already computed its Intra-APResource Allocation and consequently, the retrieval is direct andinstantaneous.

Next, at step 1520, it generates the frame COORD_AP_RESP including thebandwidth “Expected Bandwidth” and the duration “Expected Duration” asdescribed with reference to FIG. 8 . More precisely, the bandwidth“Expected Bandwidth” is included in the subfield 850 of the frameCOORD_AP_RESP 800 and the duration “Expected Duration” is included inthe subfield 851 of the frame COORD_AP_RESP 800.

FIG. 16 illustrates the general steps performed by a coordinated AP forgenerating a coordinated AP report based on the intra-AP resourceallocation, in accordance with one or more example embodiments of thepresent disclosure.

Preferably, an AP computes an Intra-AP Resource Allocation in order toschedule Its DL and UL transmissions with its associated STAs.Basically, according to IEEE 802.11ax, D6.0, when an AP gains themedium, it applies its computed Intra-AP Resource Allocation.

When a coordinated AP needs to generate a coordinated AP report (step1380), according to an embodiment of the invention, at step 1610, itretrieves its Intra-AP Resource Allocation. In such a case, the Intra-APResource Allocation corresponds to the coordinated AP Report.

Next, at step 1620, it generates the frame COORD_AP_RESP including theIntra-AP Resource Allocation as described with reference to FIG. 9 .More precisely, it extracts from its Intra-AP Resource Allocation theresources dedicated to itself and includes it in User Info field 960dedicated to the AP. And next it generates the other User Info fields970, each one corresponding to a RU allocated to an associated non-APSTA specified in its Intra-AP Resource Allocation.

FIG. 17 schematically illustrates a communication device 1700 of theradio network 100, configured to implement at least one embodiment ofthe present invention. The communication device 1700 may preferably be adevice such as a micro-computer, a workstation or a light portabledevice. The communication device 1700 comprises a communication bus 1713to which there are preferably connected:

-   -   a central processing unit 1711, such as a microprocessor,        denoted CPU;    -   a read only memory 1707, denoted ROM, for storing computer        programs for implementing the invention;    -   a random-access memory 1712, denoted RAM, for storing the        executable code of methods according to embodiments of the        invention as well as the registers adapted to record variables        and parameters necessary for implementing methods according to        embodiments of the invention; and    -   at least one communication interface 1702 connected to the radio        communication network 100 over which digital data packets or        frames or control frames are transmitted, for example a wireless        communication network according to the 802.11ax/be protocols.        The frames are written from a FIFO sending memory in RAM 1712 to        the network interface for transmission or are read from the        network interface for reception and writing into a FIFO        receiving memory in RAM 1712 under the control of a software        application running in the CPU 1711.

Optionally, the communication device 1700 may also include the followingcomponents:

-   -   a data storage means 1704 such as a hard disk, for storing        computer programs for implementing methods according to one or        more embodiments of the invention;    -   a disk drive 1705 for a disk 1706, the disk drive being adapted        to read data from the disk 1706 or to write data onto said disk;    -   a screen 1709 for displaying decoded data and/or serving as a        graphical interface with the user, by means of a keyboard 1710        or any other pointing means.

The communication device 1700 may be optionally connected to variousperipherals, such as for example a digital camera 1708, each beingconnected to an input/output card (not shown) so as to supply data tothe communication device 1700.

Preferably the communication bus provides communication andinteroperability between the various elements included in thecommunication device 1700 or connected to it. The representation of thebus is not limiting and in particular the central processing unit isoperable to communicate instructions to any element of the communicationdevice 1700 directly or by means of another element of the communicationdevice 1700.

The disk 1706 may optionally be replaced by any information medium suchas for example a compact disk (CD-ROM), rewritable or not, a ZIP disk, aUSB key or a memory card and, in general terms, by an informationstorage means that can be read by a microcomputer or by amicroprocessor, integrated or not into the apparatus, possibly removableand adapted to store one or more programs whose execution enables amethod according to embodiments of the invention to be implemented.

The executable code may optionally be stored either in read only memory1707, on the hard disk 1704 or on a removable digital medium such as forexample a disk 1706 as described previously. According to an optionalvariant, the executable code of the programs can be received by means ofthe communication network 1703, via the interface 1702, in order to bestored in one of the storages means of the communication device 1700,such as the hard disk 1704, before being executed.

The central processing unit 1711 is preferably adapted to control anddirect the execution of the instructions or portions of software code ofthe program or programs according to the invention, which instructionsare stored in one of the aforementioned storage means. On powering up,the program or programs that are stored in a non-volatile memory, forexample on the hard disk 1704 or in the read only memory 1707, aretransferred into the random-access memory 1712, which then contains theexecutable code of the program or programs, as well as registers forstoring the variables and parameters necessary for implementing theinvention.

In a preferred embodiment, the apparatus is a programmable apparatuswhich uses software to implement the invention. However, alternatively,the present invention may be implemented in hardware (for example, inthe form of an Application Specific Integrated Circuit or ASIC).

Although the present invention has been described hereinabove withreference to specific embodiments, the present invention is not limitedto the specific embodiments, and modifications will be apparent to askilled person in the art which lie within the scope of the presentinvention.

Many further modifications and variations will suggest themselves tothose versed in the art upon referring to the foregoing illustrativeembodiments, which are given by way of example only and which are notintended to limit the scope of the invention, that being determinedsolely by the appended claims. In particular the different features fromdifferent embodiments may be interchanged, where appropriate.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. The mere fact that different features are recited in mutuallydifferent dependent claims does not indicate that a combination of thesefeatures cannot be advantageously used.

1. A wireless communication method in a wireless network comprising aplurality of access points (APs) sharing a communication channel, eachAP is configured to manage stations of a basic service set (BSS), themethod comprising at a coordinator AP: gaining access to thecommunication channel; and sending to a coordinated AP a resourceallocation allocating a chunk of the communication channel for stationsmanaged by the coordinated AP, wherein the resource allocation is sentby a trigger frame in which a predetermined value for sending a resourceallocation is set.
 2. The method of claim 1, wherein the resourceallocation is determined based on resource needs obtained from thecoordinated AP.
 3. The method of claim 2, further comprising at thecoordinator AP: requesting to the coordinated AP for the resource needs.4. The method of claim 1, wherein the chunk of the communication channelis defined by frequency band, a duration and starting time.
 5. Themethod of claim 2, wherein the resource needs are indicated by bufferstatus reports (BSRs).
 6. The method of claim 2, wherein the resourceneeds are provided in a control subfield of a frame complying withIEEE802.11 series standards.
 7. The method of claim 1, wherein thetrigger frame is a frame that complies with IEEE802.11 series standards.8. A coordinator access point (AP) in a wireless network comprising aplurality of APs sharing a communication channel, each AP is configuredto manage stations of a basic service set (BSS), the coordinator APcomprising at least one microprocessor configured for carrying out stepsof: gaining access to the communication channel; and sending to acoordinated AP a resource allocation allocating a chunk of thecommunication channel for stations managed by the coordinated AP,wherein the resource allocation is sent by a trigger frame in which apredetermined value for sending a resource allocation is set.
 9. Acomputer-readable storage medium storing a program for causing a device,which functions as a coordinator access point (AP) in a wireless networkcomprising a plurality of APs sharing a communication channel, each APis configured to manage stations of a basic service set (BSS), toexecute a control method, the control method comprising: gaining accessto the communication channel; and sending to a coordinated AP a resourceallocation allocating a chunk of the communication channel for stationsmanaged by the coordinated AP, wherein the resource allocation is sentby a trigger frame in which a predetermined value for sending a resourceallocation is set.